Device for the manufacture of hollow objects.



F. J. GOLDKAMP.

DEVICE FOR THEMANUFAGTURE 0P HGLLOW OBJECTS.

APPLICATION FILED AUG. 25, 1908.

Patented Sept. 21, 1909.

glwventoz 23 a mom ble body of flexible lugs, or retaining walls.

ONE-FOURTH CALIFORNIA LIFGRNIA.

DEVICE FOR THE MANUFAUTTIRE OF HOLLOW OBJECTS.

Specification of Batters Patent. Patented Sept. 21, 1909- Application filed August 25, 1908. Serial No. 450,195. To all whom it may concern: responding parts throughout the several Be it known that I, FERDINAND J. Gonnviews.

The core comprises, an outer tube (1) and an inner tube (2) and: first of the outer tube. This member is constructed preferably,- of rubber, or like flexible material, and the terminals (3) K3311, a citizen of the United States, residing at San Diego, in the county of San Diego and State of California, have invented certain new and useful Improvements in Devices for the Manufacture of Hollow Ob jects, of which the followingxis a specification, reference being had therein to the are companying drawing.

This invention relates to the of hollow objects, such as conduits or posts, columns, ing an interna bore. lhe principle of upon the capability maining 'portion of the tube so as to insure reinforcement, and are tapered or pointed manufacture to facilitate the insertion and removal of the pipes, tubes, or or cylinders haw terminal I clench, as at 4, an externally screw threaded collar (5), which is adapted to be engaged by the complementary internal screw threads of the cap (6).

Arranged longitudinally andon the inner portion of the tube (1) is a depending seam or projection (7), the function of which Wlll presently-appear. The inner tube (2), as this designation signifies, is inclosed by the tube (1), and conforms to the contour thereof, the corresponding-pointed ends (8) be ng adapted to accommodate valves (9), which are opened or closed by the appropriate manipulation'of thecaps "6 Inthe operation of the device, a bed of suitable, material is provided, preferably, a layer of cement (10), in the trench (11), whereupon the core, in its collap'sedcoudi- 'tion, is positioned thereon as exhibited in Fig. II of the drawings. Either of the caps (6) is removed and the end of the core connected with a suitable fluid supply and the complete device distended by pressure. Additional cementis' filled in or poured in around the core and: permitted to harden, the internal pressure being maintained at such time to cause the core to bc'distended and serve as a mandrel for forming the bore the invention depends of the inflated distensi material to serve as a core or inner mold for a plastic material which applied to the exterior thereof and ellowed to indurate, the fluid pressure in the moldbeing subsequently released.

The object of theinvention is to eliminate certain objections incident to the present constructions and methods of laying, and more particularly to avoid the'presence of joints at frequent intervals, such as are found in conduits built up from short sections of previously manufactured tile or cart-henwme or other duct laid end to end in a trough or trench, to do away with the'necessity for using manholes, junction-boxes, or short junction-sections where there he sudden change of direction.

While my invention is applicable to conduits laid under ground or under water, it also useful in making and laying or installing conduits in ,other situations, as, for instance, in the erection. of hollow wall build To the accomplishment of the-recited object and others coordinate therewith, the preferred embodimentof my invention resides in that construction an arrangement of] parts hereinafter described, illustrated in the accompanying drawings, and embraced within=the scope of the appended claims.

In said drawings1-Figure I is a longitudinal section of the core. Fig. II is a trans verse section of the core in a trench, ready for inflation, and lTigsJ Ill and IV are similar views, showing respectively, the core inflated and inclosed by concrete, and the core col-lapsed. 7

Similar numerals of reference indica to corpressure may be maintained until the cementhas set sufliciently to retain theform given I toit by the distention of the core. When suitably hardened, the air or other distend- 1 ing fluid may be allowed to escape from the inner tube (2), thereby causing the core to collapse as shown in Fig. IV, this condition being accelerated by the preponderance of j It is obvithe longitudinal projection (7).

valveof thecore maybe used.

ous that either and owing to the reinforced terminals the core may be inserted or removed without a my liability of becoming ruptured.

, AND ONE-FOURTH TO of the conduit, as shown in'Fig. III. This essentially, two parts.

thereof are considerably thicker than-the rereinforcement, and are tapered or pointed It should. he understood that in its broader aspect my invention cornprehendstheemloyment not only of the means described, ut of e uivalent means for performing the recited %unctions. While the arrangement shown is thought, atthe present time to be preferable, it is desired to reserve the right to effect such modifications and variations thereof as may come fairly Within the soup of "he appended claims. I

What is claimed as new is 1. A. flexible, distensible, and collapsible core comfirising an outer tube and an inner tube, means at each end of the inner tu be'for introducing and'releasing fluid pressure, said outer tube having a longitudinal projection e a tees or seam, the preponderance of which adapted to accelerate the collapsing of the core.

2. A flexible, distensible and collapsible core having means at each end for introducin and releasing fluid pressure ..said ends being contracted and presenting a. gradual increase in thickness to serve as a reinforceinent, and a correspo nlingly shaped cap detachably mounted on each of said ends.

In testimony whereof I hereunto atfix my signature in presence of two witnesses.

FERDINAND J. GOLDKAMP. Witnesses:

A. CLARK, M. J. BAnL. 

